A sense of meaning and purpose is important for people living with acute and chronic illness. It can buffer the effects of stress and facilitate adaptive coping. As part of the Patient-Reported Outcomes Measurement Information System (PROMIS), we developed and validated an item response theory (IRT)-based measure of meaning and purpose in life.
Informed by a literature review and patient and content-expert input, we wrote 52 items to assess meaning and purpose and administered them to a general population sample (n = 1000) along with the Meaning in Life Questionnaire-Presence of Meaning Subscale (MLQ-Presence) and the Life Engagement Test (LET). We split the sample in half for exploratory factor analysis (EFA) followed by confirmatory factor analysis (CFA). IRT analyses included assessments of differential item functioning (DIF).
Participants had a mean age of 47.8 years and 50.3% were male. EFA revealed one dominant factor and CFA yielded a good fitting model for a 37-item bank (CFI = 0.962, TLI = 0.960, RMSEA = 0.085). All items were free of sex, age, education, and race DIF. Internal consistency reliability estimates ranged from α = 0.90 (4-item short form) to α = 0.98 (37-item bank). The 8-item Meaning and Purpose short form was correlated with the MLQ-Presence (r = 0.89), the LET (r = 0.79), and the full PROMIS Meaning and Purpose item bank (r = 0.98).
The PROMIS Meaning and Purpose measures demonstrated sufficient unidimensionality and displayed good internal consistency, model fit, and convergent validity. Further psychometric testing of the PROMIS Meaning and Purpose item bank and short forms in people with chronic diseases will help evaluate the generalizability of this new tool.